The bar chart in the book shows the trend of private vehicles owned by people in China.
It shows that there was a continuous increase from 1987 to 1999.

From 1987 to 1991, it was demonstrated that there is a slight increase from 500 up to 1000 vehicles per million people in China.
The graph then shows in the years 1991 to 1999 there was a sharp growth. In 1991 there were 1000 vehicles per million people and this went up to more than 4000 vehicles per million people in 1999.

It was expected that there will be a growth from 1999 onwards, but it is predicted there will be not as sharp an increase as in the years from 1991 to 1999.